1. Technical Field
The present invention relates to a light source apparatus and a projector.
2. Related Art
In recent years, a projector using a laser light source has been developed. In this kind of projector, a wavelength range of the laser light source is narrow, and thus a color reproduction range can be made sufficiently wide. In addition, miniaturization can be achieved or the number of constituent elements can be reduced.
However, when display is performed in the projector using a laser light source, light interference occurs in a scatterer such as a screen, and thus a phenomenon of a so-called speckle may occur in which bright points and dark points are distributed in a stripe shape or a patchy pattern.
The speckle can bring adverse effects since the speckle produces glaring which is unpleasant for the observer while the observer views an image. Particularly, since laser light has high coherence, there is a high possibility of speckle occurring. In addition, in the same manner, the speckle is problematic in a case of using an LED as a light source in addition to the case of using the laser light source. Even in a case of a lamp light source, light coherence has recently increased due to a shortened arc. Therefore, in the development of a projector, a technique of removing the speckle has become important.
In relation to this task, International Publication No. WO2006/090681 discloses a projector which forms an image which is projected and displayed while changing a travel direction of laser light over time by using deflection means for changing a travel direction of laser light. In International Publication No. WO2006/090681, a travel direction of laser light is changed over time, and thus a plurality of speckles may occur over time. The speckles are observed by an observer of an image in a superimposing manner over time, and, thus, according to the projector of International Publication No. WO2006/090681, an image with fewer speckles (it is hard to observe speckles) can be displayed.
The projector of International Publication No. WO2006/090681 does not remove a speckle itself. There are individual differences in a speckle-reduction effect, and thus a new speckle-reduction technique is required.